1. Field of the Invention
The present invention relates to pressure sensors comprising strips or blocks formed of materials selected to cause deflection of the strips or blocks when they are subjected to a static pressure.
2. Description of the Prior Art
Pressure sensors using diaphragms which deflect responsive to a difference between two pressures are well known. By sensing the deflection of the diaphragm in some manner, such as with capacitive sensing, the magnitude of the differential pressure acting to deflect the diaphragm can be determined. It is known that increasing "line pressure" (difference between an ambient pressure surrounding the pressure sensor and an average of the two pressures applied to the diaphragm) on a diaphragm type differential pressure sensor will cause distortions of the sensor housing. When using metal sensing diaphragms, this has been compensated for by varying the prestress level in the metal diaphragm, as well as by selecting and controlling the physical arrangement of the outer housing that deforms.
It also has been observed that when hydrostatic pressure acts on all surfaces of a body it causes the body to compress and rigidify as a function of the elastic moduli of the materials forming the body. It is also well known that a material can be selected to have a different modulus of elasticity or rate of compression from another material and thus will react differently to hydrostatic pressure. However, the deflection of a strip or member formed of two different materials coupled together having different elastic moduli when the strip is subjected to pressure has not previously been used for sensing the magnitude of such pressure.